Install fresh water cooling...or not??

[Capt. Bob]

I would like to have opinions on whether I should install a freshwater cooling system (Block only) since I am moving a freshwater boat to brackish water (Jacksonville - St. Johns River). Is it written in stone or is flushing a realistic option to say the $$.<br />The boat is a 1986 Bayliner 2850 with a Volvo (GM) 5.7 260hp I/O.<br />The engine is in good shape and I do want to preserve it, but I also do not want to spend $ if I don't have to.

 

[Bondo]

Re: Install fresh water cooling...or not??

IMHO, Spend a Little Now, Rather than Alot Later...<br />Your engine Will Rot, from the Inside Out.....<br />The Only way to Really Flush the motor, Is to run it hard in Freshwater...

 

[oldboat1]

Re: Install fresh water cooling...or not??

There is a $60 valve you can purchase that will allow you to flush the engine while the boat is still in the water. It's made by Perko, I think, and installs inline between the seacock and the water pump. When hooked up to a hose, the valve blocks the regular intake and feeds fresh water to the engine. If you flush religiously after every use, maybe you can minimize corrosion.

 

[Albe]

Re: Install fresh water cooling...or not??

I reccomend you install the FWC kit. The engine will last you longer. If you don't use the engine a lot, it will rot before you wear it out. It depends on how much you use the boat. The longer it seats without coolant, the more it will rust internally. You can always switch the kit to the next engine. Good luck.

 

[Boatist]

Re: Install fresh water cooling...or not??

Capt. Bob<br />I would not install the Half system, if you are going to do it then do the full system. Your first Saltwater problem will likely be both exhaust manifolds, not cheap to replace. If you do not catch them in time then will also have valve and cylinder damage and maybe even saltwater in your engine oil. Of course you can replace all that for about $6000.<br /><br />I have a 1980 that I run about 30 percent of the time in saltwater. So far only had to replace manifold one time and do a head Job. I have a flush adapter and always flush both engines for 10 at the wash station while wash the boat down. Also run about 70 percent of time in fresh water but any time I open up engine can always find rust and salt.<br /><br />If I had a engine that had never been in the salt I would install the Full Fresh Water System. One thing I have never been able to find out is how Long the Heat exchanger last before it needs replacing.

 

[Albe]

Re: Install fresh water cooling...or not??

Volvo engines cannot be fitted with the full system.. Only the half system is available. You might be able to trick the kit and get mercruiser manifolds and get the mercruiser FWC kit to make it a ful system, but you will have to be quite creative depending on how much space you have in your engine box. If I was you, I go half becuase I've found out that full systems require a nearly perfect cooling system to operate right. It takes a lot more to cool those manifolds than just the block. Anyways, if you stay Volvo, you can only get a half FWC kit. There is only one FWC full system kit for Volvo (for very old engines) that I've seen. I bought mine from San Juan engineering. So far, no problems at all.

 

[Boatist]

Re: Install fresh water cooling...or not??

Capt Bob<br />It appears that Albe is right only half system is available for Vovo.

 

[dmorley]

Re: Install fresh water cooling...or not??

You guys have convinced me to install a closed system on a 1998, 4.3 GM (model 4211015LS), Alpha 1 outdrive. Any recommendations on brands/models and is this something a shade tree mechanic like myself can do or should I get a pro?

 

[proline2]

Re: Install fresh water cooling...or not??

I installed mine last year on my rebuilt l984 3.8 V-6 OMC. If it had originally had the FWC then I most likely wouldn't have had to rebuild it in the first place. I think my unit came from San Juan engineering. It was an easy install except for a couple of incorrect sizes among the bushings supplied. Now the engine runs at a steadier temp and a little cooler than before. I also am not worried about cracking the block this winter because it's filled with antifreeze. <br />I absolutely agree with the comments about the engine rotting from the inside. No question about it.